core: PropertyChanged signal for Icon/class
core: PropertyChanged signal for Icon/class

This patch emits the PropertyChanged signal in the Device hierarchy when
the remote device class is updated.

pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,mapfau/bluez,ComputeCycles/bluez,pkarasev3/bluez,mapfau/bluez,mapfau/bluez,ComputeCycles/bluez,pkarasev3/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,ComputeCycles/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,silent-snowman/bluez,pkarasev3/bluez,pkarasev3/bluez,silent-snowman/bluez